
//***********************************************
//
//      Filename: homework1.java
//
//        Author: wwb
//        Mails: 1274860621@qq.com
//        Create: 2018-04-11 16:13:50
// Last Modified: 2018-04-11 16:13:50
//***********************************************
import java.util.Scanner;

public class homework1 {
    public static void main(String[] args) {
        int count;
        int sum = 1;
        System.out.println("please enter a number: ");

        Scanner scan = new Scanner(System.in);
        count = scan.nextInt();
        for (int sum1 = 1; sum1 <= count; sum1++)
            sum *= sum1;

        System.out.println(sum);


    }

}
